Electric fire-alarm.



' H. BARDITZKY.

' ELECTRIC FIRE ALARM.

APPLIQATION FILED MAY 11, 1912.

' Patented May 20, 1913.

INVENTOR Altomey cOLLmQlA PLANOGRAPH c0., WASHINGTON, 5.1:

HERMAN BARDITZKY, F MEMPHIS, TENNESSEE.

ELECTRIC FIRE-ALARM.

,T0 (ZZZ whom it may concern Be it known that I, HERMAN BARDITZKY, acitizen of the United States, residing at Memphis, in the county ofShelby and State of Tennessee, have invented certain new and usefulImprovements in Electric Fire Alarms, of which the following is aspecification. 7

This invention relates to fire alarms and particularly to electric firealarms, the ol ject being to provide an alarm of this de scription whichwill be economical to manufacture, simple in structure, not liable tobreakage or disarrangemcnt, and adjustable readily and easily whereby itwill operate at any desired degree of heat.

Vith these objects in view, the invention consists in'tlie improvedconstruction, arrangement and combination of parts hereinafter fullydescribed and afterward specifically claimed.

In order. that the construction and opera tion ofmy invention may bereadily understood, I will now proceed to fully describe a preferredembodiment illustrated in the accompanying drawings, in which- Figure 1represents a view ofmy inven-' tion 1n elevation, the circult, batteryand' bell being shown diagrammatically. Fig. 2 represents a view of thesame with the contact mechanism in longitudinal vertical sec-- tion. inelevation, and Fig. 41 represents a similar view of the opposite end.

Like reference characters mark the same parts wherever they occur in theseveral figures of the drawings.

Referring specifically to the drawings, 10

indicates a base made .of' metal which is of very slight expansibilit-yunder the influence of heat, upon which is erected near one end a block,wall or standard 11 of a nonelectric conducting ,material, having acentral threaded opening, as at 12, and at the other end a similar wall,standard or block 13 having a smooth central opening 14 in line with thethreaded opening '12 Intermediate the standards 11 and 13, is a guideblock 15, also of non-conducting material having a smooth centralopening 16 in line with the openings 12 and 1 1. Slidably fitted in theguide block 15 is a rod 17 of a metal highly expansive under theinfluence of heat,

the end of said rod being threaded as at 18 to engage in the threadedopening 12 in the standard 11. On the threaded portion of Specificationof Letters Patent. i

Application filed May 11,. 1912.

Fig. 3 represents a view of one end,

Patented May 20,1913.

Serial No. 696,664.

the rod 17 is secured a dial 19'graduated andv numbered to indicatedegrees, and having notches 20 in its periphery to receive a pawl 21secured to the standard 11. On the outside of the standard 13 isv aplate 22 of a conductive metal secured over the opening 1% by-anysuitable means, such, for instance, as screws 23. A rod 22 of conductivematerial is fitted in a central opening in the upright 13, in line withthe rod 17 and one end being twisted around the threaded end of the rod17 and the other around the rod 22 of the plate 22, said circuitincluding a source of electric current, as a battery 25 and an alarm, asa bell 26. The ends of the wire are secured by the nuts 17 and 22", thefirst nut clamping one end of the wire against the dial 19 and thesecond nut clamping the other end against. the plate 22.

By turning the rod 17, its threaded end is moved longitudinally in thethreaded 'opening 12 andits opposite end projecting beyond the guideblock 15 brought nearer to orfarther fromthe rod 22*, and the dial 19being also turned, the degree of heat at i which the alarm will besounded, will be indicated onthe dial by the pawl 21 which, engaging in.the notches 20, will also hold the dial against turning,and thuspreserve the adjusted position of the rod 17. Normally the end of therod 17 will be outof contact with the rod 22 and the circuit will bebroken, but as soon as the temperature rises to a suflicient degree, therod 17 will be expanded, and its end will contact with the rod 22 andclose the circuit through the plate 22, the wire 24, alarm 26, thebattery 25 and the rod 17, thus sounding the alarm. The rod 22 beingyieldingly held by the spring, no injury can result from over-expansionof the rod 17 due to excessive heat.

From the foregoing, the construction and operation of the invention willbe readily understood, and it will be observed that the standardscomposed of materials which are non conductors of electricity, a rodsecured in one standard and terminating near the second standard whichstandard is provided with an opening in line with the rod, anonconducting guide block in which said rod is slidable, a contact platesecured on the outside of the second standard having an open ing in linewith the opening of said standard, a second rod of conducting materialslidably mounted in the opening of the second standard, having a headedinner end, and a threaded outer end projecting through the opening inthe contact plate, an expanding spring in the opening of the secondstandard around the second rod therein, between its headed inner end andthe contact plate, and an electric circuit containing a battery andalarm and having its terminals in the ends of the two rods.

2. A fire alarm comprising a base of material but slightly expansibleunder the influence of heat, a standard of material which is anon-conductor of electricity erected at one end of the base and having acentral threaded opening, a second standard 01": non-conducting materialerected at the opposite end of the base and provided with a smoothcentral opening, a rod of conducting material more expansive than thebase under influence of heat having one end threaded and engaged in thethreaded opening of the first standard and the other end smooth andterminating near the second standard, a contact plate on the outside ofthe second standard having an opening in line with the highly expansiverod, a contact rod slidably fitted in the opening of the second standardand the contact plate and having a threaded end, a nut on said threadedend outside of the contact plate, a graduated dial secured on thethreaded end of the highly expansive rod and having notches in itsperiphery, a pawl secured to the first standard and engaging saidnotches, and an electric circuit containing a battery and alarm andhaving its terminals in the threaded ends of the two rods.

In testimony whereof I atlix my signature in presence of two witnesses.

HERMAN *KARDITZKY. Witnesses J. A. Bownns, A. Tosrr, Jr.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

